KR20220154769A - Unmanned transport vehicle equipped with a load lifting device - Google Patents

Abstract

The present invention relates to an unmanned, in particular automatically guided, transport vehicle (1) for transporting a payload, in particular a transport vehicle (1) having a payload lifting device (2) as a material transport vehicle in a plant. For a particularly cost-effective, still robust and efficient construction of the lifting device 2, according to the invention, the lifting process is realized by means of an eccentric drive.

Description

Unmanned transport vehicle equipped with a load lifting device

The present invention relates to an unmanned, particularly self-guided, preferably autonomous self-guided transport vehicle for carrying a payload. Such vehicles are generally used as so-called industrial trucks or material transport vehicles in manufacturing plants, for example to transport specific loads within a warehouse or from a warehouse to a manufacturing line, preferably while driving autonomously.

In the case of such a transport vehicle, the load may be composed directly of the payload itself and a payload carrier on which the payload can be separately loaded, for example, a rack, roller trolley, or the like. Here, it is intended that a transport vehicle drives under such a payload carrier, independently raises the payload carrier, transports the payload carrier to a destination, and can put the payload carrier down there again. do. For this purpose, transport vehicles are equipped with an integrated lifting device.

Various solutions are conventionally known for implementing the lifting function. In order to be able to lift large loads quickly and accurately, lifting devices require high rigidity, and high power motor configurations and correspondingly high electrical energy demands, which result in higher weight, larger batteries, higher costs, or more It entails a short driving range.

DE 102013013438 A1 discloses, for example, a transport vehicle in which the lifting function is implemented via various thrust and lever devices, which, due to its design principle and rigidity requirements, exhibit a high system weight and require large structural space requirements. have

EP 102706 A1 discloses another transport vehicle in which the lifting device is configured with a ball screw drive, which is complex to manufacture and relatively expensive.

Against this background, the object of the present invention is to propose a transport vehicle with a lifting device which can be made of the most inexpensive and at the same time as robust and efficient construction as possible.

This object is achieved by a combination of the features recited in the independent claims. Other embodiments and refinements of the invention appear in the dependent claims and in the following description and drawings.

The present invention provides that the lifting operation is carried out via an eccentric drive. A simple, inexpensive and robust low-maintenance solution for lifting and maintaining large loads can be realized with this.

In order to realize a construction of a transport vehicle that is particularly compact and advantageous from a maintenance point of view, the transport vehicle has a flat undercarriage in which driving components are arranged, height-adjustable to the undercarriage and serving to carry a load. and at least one load carrier element. Here, the eccentric drive has at least one rotatably mounted eccentric element which introduces a lifting force into the load carrier element during the lifting operation. Through this, the upward travel can be defined structurally easily and effectively through the configuration of the eccentric element, operational reliability is increased, and malfunctions and breakdowns are prevented.

According to one advantageous refinement of the invention, for reliable lifting synchronization, the lifting device comprises a lifting shaft extending transversely through substantially the entire undercarriage and having in each case an eccentric element at opposite ends. include Accordingly, also, the lifting operation can be carried out easily and inexpensively via a single drive unit acting on the lifting shaft.

According to one preferred embodiment, for the purpose of powerful transmission of forces from the drive unit to the lift shaft and at the same time a particularly flexible and effective utilization of the structural space, the lift shaft is actuated by means of a wraparound drive.

For efficient guidance and support of the load carrier element, which can be implemented inexpensively, at least one outer periphery of the opening of the load carrier element guides the load carrier element in the lifting direction and supports it transversely to the lifting direction. , wherein the opening is configured so that a lift shaft extends therethrough.

According to a further refinement of the invention, for a further improved guidance and support of the load carrier element, which is formed, on the end side, parallel to the direction of elevation and bears the corresponding area of the undercarriage in the longitudinal direction, its It has a flat surface that slides on top.

According to a preferred embodiment, for a stable and at the same time weight-saving construction, the transport vehicle has in each case two load carrier elements arranged oppositely on either side of the chassis.

To increase the rigidity or enhance the functional range, the two load carrier elements can be connected to each other by means of at least one transverse connection.

For an easily implemented robust synchronization of the lifting device in the longitudinal direction, one preferred embodiment of the invention is that the lifting device comprises at least two eccentrics acting on the same load carrier element and coupled to each other by means of a wraparound drive. Provides having elements.

According to a particularly preferred embodiment of the invention, the eccentric element has a rolling bearing element which is arranged radially from the outside and which rolls on the load carrier element during the lifting operation. Thus, the eccentric element and its counterbearing do not need to be strengthened to reduce wear. Likewise, it is possible to omit maintenance-intensive lubricants that are prone to contamination, or sliding coatings that are prone to wear. Moreover, the drive motor does not have to overcome the large frictional resistance between the eccentric element and its counter bearing in addition to the load. The power of the drive unit can be reduced for less structural space and lower energy consumption, or larger loads can be lifted and transported.

According to a preferred embodiment, the lifting device may comprise four eccentric elements coupled to each other, forcibly synchronously movable, and serving to raise and lower a load.

Accordingly, an uninterrupted and uniform lifting and lowering of the load can be realized purely mechanically without additional control technology costs.

The present invention will be discussed in more detail below based on exemplary embodiments.
1 is a highly simplified view of a transport vehicle, showing a top view of the lifting device ( FIG. 1A ), a side view of the retracted lifting device ( FIG. 1B ) and a side view of the deployed lifting device ( FIG. 1C ).
FIG. 2 shows a view according to FIG. 1 , additionally with a loaded load carrier.
3 is an illustration of an embodiment of a transport vehicle in which a payload is in a payload carrier.
Fig. 4 is a three-dimensional view of some elements of the chassis and lifting device (Fig. 4a), and an enlarged view of the guidance in the opening of the load carrier element (Fig. 4b).
FIG. 5 shows a partial side view of some elements of the transport vehicle 1 and the lifting device 2 in a raised transport position ( FIG. 5a ) and a lowered parking position ( FIG. 5b ).
6 shows an embodiment of an eccentric element with a rolling bearing element.
7 shows a detailed view of the driving part of the lifting shaft.

Figure 1

The driverless transport vehicle 1 serves in particular to transport loads on smooth floors in manufacturing and assembly plants, for example for the purpose of transporting parts and components to/from a manufacturing line or within a parts warehouse. The transport vehicle 1 autonomously selects a driving route based on an integrated spatial monitoring sensor and control system (emphasized here and not shown).

The transport vehicle 1 has a flat and compact undercarriage 8 with all control and drive components arranged in and on it.

In the illustrated embodiment, the transport vehicle 1 moves on a pair of support wheels 15 and a pair of drive wheels 14 . The driving wheels 14 are individually drivable independent of each other and serve to propel and steer the transport vehicle 1 .

For the transport of loads or the placement of loads, the transport vehicle 1 has two load carrier elements 9 , 9 ′ which form part of the lifting device 2 . The load carrier elements 9, 9' are of elongated form in the longitudinal direction or parallel to the direction of travel F and are located on the lateral sides of the undercarriage 8 in the upper region. In the illustrated embodiment, each load carrier element 9, 9' consists of a box-shaped hollow body. To lift the load, the load carrier elements 9, 9' can be lifted in a vertical lift direction H by means of a lift run 16 from the retracted parking position (Fig. 1b) to the deployed transport position.

The load carrier elements 9, 9' may be cross-connected via one or more struts, strips or panels (not shown here), for example to increase rigidity and/or to realize a wider flat load surface. Yes (21).

Figure 2

The transport vehicle 1 is primarily designed to transport payloads in separate payload carriers 6 . The load carrier 6 may be configured in various forms (such as a form of a rack as shown, a form of a trolley or a roller trolley, etc.).

The payload carrier 6 is configured in such a way that the transport vehicle 1 with the load carrier elements 9 , 9 ′ in a parked position can drive underneath the payload carrier 6 . The load carrier 6 has two traverses 7, 7' running transverse to the direction of travel, on which load carrier elements are supported during lifting and transport of the load carrier 6. In the embodiment shown, the traverses 7, 7' are connected via two externally located longitudinal members 17, 17'.

To transport the load, the transport vehicle 1 drives under the loaded load carrier 6 and activates the lifting device 2 . Here, the load carrier elements 9, 9' are raised in the lifting direction H, abut the traverses 7, 7', and lift the loaded load carrier 6 from the floor. As a result, the loaded load carrier 6 is transported to its destination, and there it can be put back on the floor in reverse order.

Figure 3

FIG. 3 shows an exemplary usage scenario of the transport vehicle 1 and substantially corresponds to the situation shown in FIG. 2B . The embodiment of the transport vehicle 1 is located below the payload carrier 6 which consists of a roller trolley. On the payload carrier 6, a payload 22 composed of a wire-mesh box filled with sacks is loaded.

Figure 4

4 shows some structural elements of the chassis 8 together with the components of the lifting device 2 .

The lifting device 2 has a lifting shaft 10 rotatable about a rotational axis D, which extends transversely through substantially the entire undercarriage 8, so that its ends carry two opposite load bearings. It is engaged with the carrier element 9, 9'. In each case one disc-shaped eccentric element 3 , 3 ″ is arranged to be fixed in a joint rotational manner on both ends of the elevating shaft 10 . Overall, the lifting device 2 has four disk-shaped eccentric elements 3, 3', 3'', 3''' which support the load carrier elements 9, 9' in the vertical direction.

Each load carrier element 9, 9' has an opening 11 into which a lifting shaft is engaged. Each opening is of elongated form in a vertical direction and has two straight periphery portions 12 oriented parallel to each other and to the upward direction H. By means of these two outer circumferences 12, forces acting in particular parallel to the travel direction F or transverse to the lift direction H are transferred from the load carrier element 9 to the elevating shaft 10 and thus to the elevating shaft 10. It is introduced into the chassis 8. In this way, the outer circumferences 12 serve to support and guide forces on the load carrier elements 9, 9'.

Furthermore, each load carrier element 9, 9' has, on the end side, a flat surface portion 13, 13' formed parallel to the lifting direction H. These surface parts 13 , 13 ′ likewise serve for vertical guidance during the lifting operation and support and introduction of longitudinal forces into the undercarriage 8 .

Fig. 5

FIG. 5 shows several elements of the transport vehicle 1 and the lifting device 2 in a raised transport position ( FIG. 5a ) and in a lowered parking position ( FIG. 5b ), with the side wall of the load carrier element 9 removed. A partial side view is shown.

On each side of the transport vehicle 1 , the lifting device 2 has in each case two eccentric elements 3 , 3 ′ of equal size, which act on the same load carrier element 9 . Here, the drive-side eccentric element 3 seated on the lift shaft 10 is coupled to the other output-side eccentric element 3' by the wrap-around drive unit 18, and accordingly, when the lift shaft 10 rotates , both eccentric elements 3, 3' rotate simultaneously in the same direction. In this embodiment, the wraparound drive 18 is implemented as a chain drive. However, other embodiments, for example in the form of a toothed belt drive, remain acceptable within the present invention as well.

To perform the lifting movement, the rotational movement of the lifting shaft 10 is converted into a translational movement of the load carrier element 9 parallel to the lifting direction H by means of the eccentric elements 3, 3'. The upper horizontal rail of the load carrier element 9 serves as a counter bearing for the eccentric elements 3, 3'. In order to reduce the friction between the eccentric elements 3, 3' and the load carrier element 9, each eccentric element 3, 3' is equipped, radially from the outside, with a rolling bearing element 4. , whereby the eccentric element rolls quietly and with low friction on the counter bearing. By means of the outer circumferences 12 and the surface part 13 of the opening 11 as already mentioned above, the rise, which occurs as the eccentric elements 3 , 3 ′ roll on the load carrier element 9 Force components directed transversely to direction H are introduced into the undercarriage 8 .

Fig. 6

6 shows an embodiment of the eccentric element 3 . A rolling bearing element 4 is located at the radially outer edge of the eccentric disk 24 . In the illustrated embodiment, the rolling bearing element 4 consists of a ball bearing pressed onto an eccentric disk 24 . However, within the present invention it is equally contemplated that the eccentric disk 24 itself constitutes a component of a rolling bearing, for example an inner ring.

The lifting run 16 of the lifting device 2 is structurally defined by twice the radial distance between the rotational axis D of the center of the lifting shaft receptacle 23 and the center point M of the eccentric disk 24 .

Fig. 7

FIG. 7 shows a preferred embodiment of the actuation of the lifting shaft 10 by means of a wraparound drive 19 activated by an electric drive unit 20 . Accordingly, the drive unit 20 functions as a lift driver of the lift device 2 .

In the preferred embodiment shown, the wraparound drive 19 is provided as a chain drive. However, within the present invention, it may have some other configuration depending on requirements, for example in the form of a belt drive.

1 transport vehicle
2 lifting device
3 eccentric elements
4 rolling bearing elements
5 counter bearing
6 payload carriers
7 traverse
8 chassis
9 load carrier elements
10 lifting shaft
11 openings
12 outer periphery
13 surface
14 driving wheel
15 support wheel
16 Rise run
17 Longitudinal members
18 wraparound driving unit
19 wrap-around driving unit
20 drive unit
21 transverse connection
22 Payload
23 elevating shaft receptacle
24 eccentric disc
M center point
D axis of rotation
F driving direction
H rising direction

Claims (11)

An unmanned, in particular automatically guided, transport vehicle (1) for transporting a load, comprising a lifting device (2) configured to elevate the load so that the load can be transported in an elevated state, the lifting operation comprising: Transport vehicle (1), characterized in that it is implemented via an eccentric drive. 2. The transport vehicle (1) according to claim 1, wherein the transport vehicle (1) has an undercarriage (8) with driving components arranged therein, and the elevating device (2) is height-adjustable relative to the undercarriage (8) and is loaded. at least one load carrier element (9) serving to carry a load, said eccentric drive at least one rotatably mounted eccentric element ( A transport vehicle (1) characterized by having 3). 3. The lifting device (2) according to claim 2, wherein the lifting device (2) extends transversely through substantially the entire undercarriage (8) and is provided at opposite ends in each case with one eccentric element (3, 3''). Transport vehicle (1), characterized in that it comprises an elevating shaft (10). 4. Transport vehicle (1) according to claim 3, characterized in that the elevating shaft (10) is actuated by a wraparound drive (19). 5. The method according to at least one of claims 3 and 4, wherein the load carrier element (9) has at least one opening (11) through which the elevating shaft (10) extends, at least one of the openings (11). characterized in that the outer periphery (12) of is configured for guidance of the load carrier element (9) in the lifting direction (H) and for support transverse to the lifting direction (H) on the lifting shaft (10). transport vehicle (1). 6. The load carrier element (9) according to at least one of claims 2 to 5, which is formed, on the end side, parallel to the lifting direction (H) and forces into the undercarriage (8) in the longitudinal direction. A transport vehicle (1), characterized in that it has a flat surface portion (13) provided for the introduction and support of. 7. The transport vehicle (1) according to at least one of claims 2 to 6, wherein the transport vehicle (1) has in each case two load carrier elements (9, 9') arranged oppositely on either side of the chassis (8). A characterized transport vehicle (1). 8. Transport vehicle (1) according to claim 7, characterized in that the two load carrier elements (9, 9') are connected to each other by means of at least one transverse connection (21). 9. The lifting device (2) according to at least one of claims 2 to 8, wherein the lifting device (2) has at least two eccentric elements acting on the same load carrier element (9) and coupled to each other by means of a wraparound drive (18). A transport vehicle (1) characterized by having (3, 3'). 10. The method according to at least one of claims 2 to 9, wherein the eccentric element (3) comprises a rolling bearing element (4) which is arranged radially from the outside and which rolls on the load carrier element (9) during the lifting operation. A transport vehicle (1) characterized in that for doing. 11. The device according to at least one of claims 1 to 10, wherein the lifting device (2) comprises four eccentric elements (3, 3', 3'', 3''').

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